Abstract
The unique possibilities of rapid thermal processing (RTP) for overcoming two significant challenges in the development of oxide thin-film photoelectrodes are demonstrated. The first is the need to exceed normal temperature limits for glass-based F:SnO2 substrates (FTO, ∼550 °C) to achieve the desired density, crystallinity, and low defect concentrations in metal oxides. Flash-heating of Ta2O5, TiO2, and WO3 photoelectrodes to 850 °C is possible without damaging the FTO. RTP heating-rate dependencies suggest that the emission spectrum of the RTP lamp, which blue-shifts with increasing heating power, can significantly influence the crystallization behavior of wide-bandgap photoelectrodes (≥1.8 eV). The second challenge is avoiding the formation of structural defects, trap states, grain boundaries, and phase impurities, which can be particularly difficult in multinary metal oxides. RTP treatment of α-SnWO4, a promising photoanode material, resulted in an increase in grain size and favorable crystallographic reorientation, culminating in a new performance record.
Original language | English |
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Pages (from-to) | 514-522 |
Number of pages | 9 |
Journal | ACS Energy Letters |
Volume | 7 |
Issue number | 1 |
DOIs | |
State | Published - 14 Jan 2022 |
Externally published | Yes |
Bibliographical note
Funding Information:The authors acknowledge Marco Favaro for fruitful discussions, Rene Gunder for XRD user support, and Christian Höhn and Karsten Harbauer for technical support. The authors also thank Stefan Würl for his experimental assistance.
Publisher Copyright:
© 2022 American Chemical Society